Astronomers puzzled over huge black hole in the middle of small galaxy

The object at the center is NGC 1277, a compact galaxy harboring one of the most massive black holes known.

David W. Hogg/Michael Blanton/SDSS Collaboration

The supermassive black holes occupying the centers of most galaxies have a close relationship with their galactic hosts. Galaxies with large central bulges have massive black holes, while the relatively lightweight black holes live in galaxies with smaller bulges. This link has been observed in enough cases to raise it nearly to a principle: black holes and galactic bulges grow together, as part of a single process.

A new observation has revealed a galaxy that isn't just bending the rule, but completely breaking it. In most systems, the black hole's mass is about 0.1 percent of the mass of the galaxy's central bulge. Remco van den Bosch and colleagues identified a black hole with a mass that's about 59 percent of the mass of the central bulge. In fact, this black hole is one of the most massive ever observed, a striking discovery in a galaxy much smaller than our own. The galaxy itself is a bit on the small side, and the researchers suggest that we might want to look at the black holes in more galaxies this size.

Supermassive black holes, as their name suggests, have masses millions to billions of times that of our Sun. The Milky Way's black hole, for example, is about 4 million times the Sun's mass, while the black hole in the giant galaxy M87 tips the scale at 6.6 billion solar masses. While these black holes constitute the most massive single objects known, they don't dominate the mass of their host galaxies, and (with the exception of the newly studied galaxy) they don't even dominate the mass of the galactic bulge: the Milky Way's bulge is approximately 20 billion solar masses.

Galaxies such as the Milky Way divide into three basic regions: disk, which contains the brightest and youngest stars, as well as the spiral arms; the bulge at center, which has older stars; and the halo surrounding the luminous portions. Nearly every galaxy appears to contain a supermassive black hole in its central bulge. Studies of a large number of galaxies have revealed a close relationship between the mass of the central black hole and the size of the galactic bulge.

The current study examined NGC 1277, a lenticular galaxy (meaning lens- or lentil-shaped, depending on proximity to lunchtime). Lenticular galaxies resemble spiral galaxies (the category including the Milky Way and our nearest large neighbor, Andromeda), but lack the spiral arm structure. NGC 1277 is relatively compact, with a total mass around 120 billion times that of the Sun, approximately 1/10 the Milky Way's mass. Additionally, NGC 1277 lacks a significant bulge; the published paper made reference to a "pseudo-bulge" due to the lack of well-defined bulge characteristics.

Measuring the mass of a black hole typically requires measuring the spectrum of gas and stars in the central regions and obtaining a good image of the galaxy. To this end, the researchers used the 11-meter Hobby-Eberly Telescope (HET) in Texas, an instrument suited to high-resolution spectral imaging. They measured the motion of material near the centers of 700 galaxies, and discovered six—including NGC 1277—with stars that were moving much faster than expected. This indicates that something massive is accelerating the gas and stars beyond the speeds typical in similar galaxies. The observations also revealed that more of each galaxy's mass was concentrated in its central region than expected.

Of the six studied, only NGC 1277 was also the subject of a high-resolution image, taken using the Hubble Space Telescope. The researchers used the available data to obtain the most likely values for several galactic parameters, including the bulge mass and the black hole mass. They found the central black hole most likely had a mass between 14 billion and 20 billion times the Sun's—significantly larger than most previously observed black holes in any galaxy. Given it's in a relatively small galaxy, the black hole appeared amazingly out of proportion: 59 percent of the estimated bulge mass, and 14 percent of the total mass of NGC 1277.

Since supermassive black holes are typically proportional to the bulge mass, these results were striking. NGC 1277 contains many old stars, and shows no signs of being heavily distorted by interactions with other galaxies. This means NGC 1277 is unlikely to have been the remnants of a much larger galaxy, ruling out the possibility that the black hole and galaxy grew normally before some of the galaxy's stars were stripped.

The existence of five more compact galaxies with rapidly moving matter in the central regions could suggest that disproportionately oversized black holes are not unique to NGC 1277. Further observations should settle that question.

Why should such a huge black hole live in such a small galaxy? The astronomers (probably wisely) remained silent on this question, since the clear data come from only one sample. But whether outsized black holes reside in many compact lenticular galaxies or just in NGC 1277, we'd still need to explain how the usual, well-established relationship between black hole and bulge masses could be violated so dramatically.

(The author wishes to acknowledge that a lot of sophomoric dirty jokes will be made about the terminology in this article. He has thought of them all, so there is no need to leave them in the comments section.)

(The author wishes to acknowledge that a lot of sophomoric dirty jokes will be made about the terminology in this article. He has thought of them all, so there is no need to leave them in the comments section.)

Well hey, you brought it up. When you leave a hole wide open like that it'd be a violation not to fill it with some bulge.

Why are we "puzzled" or surprised by anything anymore? Looking at the vastness of space and all it contains, to the quirkiness of the quantum world, isn't it clear by now that in the grand scheme of things, we don't know jack?

(The author wishes to acknowledge that a lot of sophomoric dirty jokes will be made about the terminology in this article. He has thought of them all, so there is no need to leave them in the comments section.)

Well hey, you brought it up. When you leave a hole wide open like that it'd be a violation not to fill it with some bulge.

This brings back memories of how difficult it was to make it through astrophysics in college. It was definitely one of the fun/easy classes in the physics department, but also a lot of room for juvenile jokes.

(The author wishes to acknowledge that a lot of sophomoric dirty jokes will be made about the terminology in this article. He has thought of them all, so there is no need to leave them in the comments section.)

Well hey, you brought it up. When you leave a hole wide open like that it'd be a violation not to fill it with some bulge.

Could we be looking at the galaxy at a time when the black hole already swallowed most of the mass, and we're see what's left?

Black holes are largely self-regulating. The faster they ingest, the hotter the accretion disk around them gets, which blows back the gas and dust and slows the feeding rate.

The fact is we don't have a good explanation for how supermassive black holes get supermassive. Part of the problem is the lack of intermediate mass black holes. We see lots of small ones (< 100 solar masses), and lots of supermassive ones (> 100,000 solar masses). But we don't see anything in between. It's like looking at a human embryo and Andre the Giant and trying to figure out how to get from A to B. From a trillion miles away.

So it's not that we understand how other supermassive black holes get their size. We don't. It's just that up to now, they've followed a very consistent pattern of being directly related to the mass of the bulge of their host galaxy. So whatever explanation we eventually come up with to explain how supermassive black holes are made now also needs to explain this one. And it's a doozy.

The fact is we don't have a good explanation for how supermassive black holes get supermassive. Part of the problem is the lack of intermediate mass black holes. We see lots of small ones (< 100 solar masses), and lots of supermassive ones (> 100,000 solar masses). But we don't see anything in between. It's like looking at a human embryo and Andre the Giant and trying to figure out how to get from A to B. From a trillion miles away.

Fascinating. Do we have any knowledge about when supermassive vs. merely massive blacks holes form? IOW, are supermassives all products of the early Universe, or have they been forming "recently"? Do we know if this particular galaxy is unusually young or old compared to similar-sized galaxies?

Why are we "puzzled" or surprised by anything anymore? Looking at the vastness of space and all it contains, to the quirkiness of the quantum world, isn't it clear by now that in the grand scheme of things, we don't know jack?

I understand what you are attempting to convey but new findings are still exciting and surprising.

You can say 'Anything is possible - the universe is huge' but to be able to see something new and study it and confirm it - now that is something completely different.

Could we be looking at the galaxy at a time when the black hole already swallowed most of the mass, and we're see what's left?

Black holes are largely self-regulating. The faster they ingest, the hotter the accretion disk around them gets, which blows back the gas and dust and slows the feeding rate.

The fact is we don't have a good explanation for how supermassive black holes get supermassive. Part of the problem is the lack of intermediate mass black holes. We see lots of small ones (< 100 solar masses), and lots of supermassive ones (> 100,000 solar masses). But we don't see anything in between. It's like looking at a human embryo and Andre the Giant and trying to figure out how to get from A to B. From a trillion miles away.

So it's not that we understand how other supermassive black holes get their size. We don't. It's just that up to now, they've followed a very consistent pattern of being directly related to the mass of the bulge of their host galaxy. So whatever explanation we eventually come up with to explain how supermassive black holes are made now also needs to explain this one. And it's a doozy.

I thought there are two common theories on how supermassive black holes can form. The first is from early periods in the Universe shortly after the big bang. Lots of matter in a relatively low volume of space allowed supermassive stars to form that had short lifetimes. These were the first black holes and they had lots of mass to feed off of when the stars collapsed. They also performed a vital function of ejecting mass away from them via their accretion disc jets allowing the universe to expand and not collapse under all the gravity produced by these monsters(that, and dark energy, whatever that is).

The second is through black hole mergers. Pretty self explanatory there.

Black holes are largely self-regulating. The faster they ingest, the hotter the accretion disk around them gets, which blows back the gas and dust and slows the feeding rate.

The fact is we don't have a good explanation for how supermassive black holes get supermassive. Part of the problem is the lack of intermediate mass black holes. We see lots of small ones (< 100 solar masses), and lots of supermassive ones (> 100,000 solar masses). But we don't see anything in between. It's like looking at a human embryo and Andre the Giant and trying to figure out how to get from A to B. From a trillion miles away.

So it's not that we understand how other supermassive black holes get their size. We don't. It's just that up to now, they've followed a very consistent pattern of being directly related to the mass of the bulge of their host galaxy. So whatever explanation we eventually come up with to explain how supermassive black holes are made now also needs to explain this one. And it's a doozy.

I'll admit, as a fascinated observer, I was a little disappointed that the author and the scientists didn't speculate on what could explain this. Your insight has put things in perspective and filled that void for me. Thanks!

One thought, and I could be wrong, but isn't it possible that a large black hole can form without a large galaxy bulge? I'm not saying it could be super common but couldn't it "just" happen? I'm not sure how, but if during the early formation of the galaxy most of the mass was towards the center it would make sense that the formation of the black hole could have been massive, and then left little mass elsewhere.

I guess one way it could have happened was if it formed in a cluster, and the various gravity dynamics could have resulted in one rare galaxy with a lot of mass squished together.

I know nothing about astrophysics (or physics at all actually!) so I'm just guessing completely off the top of my head. Please be gentle tearing my theory to confetti and just make sure it is smaller then police records used in the Macy's Thanksgiving Day Parade!

Galaxies are generally formed by all the materials around them. Maybe whatever process creates the black hole relies on something other than amount of junk you have available. Say a certain element allows for larger black holes to form. In larger galaxies with larger black holes, this element might have been really common with a lot of other elements that will form the stars/planets eventually. Perhaps this black hole was formed by a lot of this element being in one place, and there was little left over of the other elements to create the stars/planets and you get... this?

Perhaps these smaller galaxies are remnants of a collision where another, larger galaxy stripped most of its stars away?

That is one of the theories they looked at, but it doesn't look likely. It is pretty easy to tell if a galaxy has had collisions, since a collision destroys or distorts the spiral structure. If spirals merge, they form elliptical galaxies, which don't have disks at all; if spirals come close but don't merge, the forces still destroy the spiral structure, basically stretching the arms and ripping them off the galaxy. They don't see any evidence of that sort of disruption in this galaxy.

Why are we "puzzled" or surprised by anything anymore? Looking at the vastness of space and all it contains, to the quirkiness of the quantum world, isn't it clear by now that in the grand scheme of things, we don't know jack?

We're puzzled and surprised by things beyond our understanding. We expect to find lots of things we don't understand, but simply expecting to find new things doesn't negate the desire to understand them (causing puzzlement) or the wonder at their existence (surprise.)

EG Right now we don't have any good theory of quantum gravity. We expect to find one eventually, it will probably involve a graviton (quantum of the gravitational field), and we expect to be puzzled by quite a lot of the evidence leading up to the discovery of such a quantum. Physics beyond the Standard Model is sure to be exciting, new, and unexpected in the specifics, even if we know some of the general concepts that will be needed.

Anyone who isn't puzzled and surprised by a new discovery isn't likely to be a scientist.

Black holes are largely self-regulating. The faster they ingest, the hotter the accretion disk around them gets, which blows back the gas and dust and slows the feeding rate.

The fact is we don't have a good explanation for how supermassive black holes get supermassive. Part of the problem is the lack of intermediate mass black holes. We see lots of small ones (< 100 solar masses), and lots of supermassive ones (> 100,000 solar masses). But we don't see anything in between. It's like looking at a human embryo and Andre the Giant and trying to figure out how to get from A to B. From a trillion miles away.

I'm wondering about that, too. As far as I understand things, even black holes only have gravity to collect stuff. So for example if our sun would become a BH over night, earth would still happily circling around it for aeons (though your solar panel wouldn't work anymore...). So the only way becoming supermassive is that mass had to be tightly packed form the beginning on. I think for this special galaxy, mass was anormal thightly packed on formation.

I think the most popular current explanation for supermassive formation is by merger. The story is, you start with an early Universe with smallish galaxies and reasonably sized black holes at the center (maybe the mass of a large globular cluster that didn't have enough angular momentum to survive collapse, being at the center of the cloud that formed the galaxy). Then these galaxies start eons of mergers with the black holes feeding along the way, and after billions of years of collisions and central black hole mergers, you see the monsters of today. Simulations show it's plausible (growth is exponential, as each cycle of merging doubles the mass of the central black holes, so mass increases a millionfold after 20 mergers), and we've observed black hole mergers directly. This gets the size correlation correct, as the more mergers of a galaxy, the more mergers of its black hole, but allows for outliers like this where for some reason a black hole lost its galaxy after undergoing many mergers, perhaps by being ejected from its galaxy by an ancient collision and carrying only a small region of surrounding stars with it.

Small galaxy, massive black hole, old in age. The black hole likely ate a large portion of its galaxy already. Isn't that the likely scenario? How else do black holes become massive? Surely it ate to become so big?

Small galaxy, massive black hole, old in age. The black hole likely ate a large portion of its galaxy already. Isn't that the likely scenario? How else do black holes become massive? Surely it ate to become so big?

Mostly supermassives eat other supermassive black holes, not their galaxies.

Part of the problem is the lack of intermediate mass black holes. We see lots of small ones (< 100 solar masses), and lots of supermassive ones (> 100,000 solar masses). But we don't see anything in between.

FWIW:

"The most elegant part of the new study is how the researchers used the mere presence of the plasma jets to calculate the black hole's size far more precisely than with the X-rays alone. X-ray intensity correlates to the amount of matter falling into the hole, while radio emissions correlate to the strength of the exiting jets — and both appear to have a constant, scaled relationship to the mass of a black hole. If you know that constant — and it's a pretty standard equation in the astrophysicist's toolbox — you can calculate the mass of the body. While the X-ray readings put the black hole at the very low end of the medium range, the plasma jets boosted it higher — from just 500 solar masses to somewhere between 9,000 and 90,000. That's a big range, but for a first discovery, it's not too shabby. Indeed, says Webb, her calculations represent "the most refined estimate of the mass of HLX-1 and indeed any intermediate-mass black hole proposed to date.""

"Though HLX-1 is getting all the attention at the moment, researchers are investigating other potential medium-size black holes, including objects within globular clusters in the constellation Pegasus and the Andromeda galaxy. Astrophysicists are also focusing on low-mass "dwarf galaxies" that have had very little interaction with other galaxies, hoping to find intermediate-mass black holes hidden somewhere inside like treats in a cereal box.

In the meantime, studies of HLX-1 will continue. "I am very excited that we have finally found the observational evidence to substantiate these theoretically proposed objects," Webb says. It seems HLX-1 is one middle child that will not be neglected." [ Monday, July 09, 2012, http://www.time.com/time/health/article ... 50,00.html ]

Why are we "puzzled" or surprised by anything anymore? Looking at the vastness of space and all it contains, to the quirkiness of the quantum world, isn't it clear by now that in the grand scheme of things, we don't know jack?

The method of science is to be ""puzzled" or surprised by anything", that is the only way it can progress and give us testable knowledge.

Theories predict observations, and so both constitute testable knowledge. It is therefore so that our theories knows more than isolated (and sometimes surprising) observations do.

Galaxies are generally formed by all the materials around them. Maybe whatever process creates the black hole relies on something other than amount of junk you have available. Say a certain element allows for larger black holes to form. In larger galaxies with larger black holes, this element might have been really common with a lot of other elements that will form the stars/planets eventually. Perhaps this black hole was formed by a lot of this element being in one place, and there was little left over of the other elements to create the stars/planets and you get... this?

Maybe that element is element zero.... (sorry, been playing way too much Mass Effect lately).

cdclndc wrote:

aardarf wrote:

Quote:

(The author wishes to acknowledge that a lot of sophomoric dirty jokes will be made about the terminology in this article. He has thought of them all, so there is no need to leave them in the comments section.)

Well hey, you brought it up. When you leave a hole wide open like that it'd be a violation not to fill it with some bulge.

....queues Barry White tunes..

Why did the sophomoric joke get upvoted (+21/-5 as of this writing) but the Reply got downvoted (+1/-6). Do you guys just not like Barry White? I really don't understand the logic of the voting system...

Edit: Wow, anybody want to comment onto why I was downvoted? I'd like the feedback to improve my commenting. Was it the Mass Effect Reference, The Barry White music, or the commenting on the upvote / downvote system (my guess is the last one)

Why are we "puzzled" or surprised by anything anymore? Looking at the vastness of space and all it contains, to the quirkiness of the quantum world, isn't it clear by now that in the grand scheme of things, we don't know jack?

Sure, sure, that's one viewpoint: anything is possible (or rather we don't know it isn't) so nothing should be surprising.

Another viewpoint is that even though anything is possible, you can't expect "anything", in fact you don't, so it's surprising when the unexpected anything shows up.

An example:

Lets say that after several thousand days of living alone in an apartment, establishing a solid pattern of bachelorhood, one day you came home and found something unexpected: A family of Sasquatch sitting around your dining room table playing Parcheesi.

Do you A) shrug with a mental note that "anything is possible" and join them?

or B) express a certain amount of surprise, restrained perhaps so as not to alarm the notoriously shy creatures, and then join them and/or panic and run screaming while trailing a stream of urine?

(The author wishes to acknowledge that a lot of sophomoric dirty jokes will be made about the terminology in this article. He has thought of them all, so there is no need to leave them in the comments section.)

I wonder if a sophomore invented the term "bulge" (they say most science is discovered early in careers). Either that or an old professor with a penchant for WWII history did.

(The author wishes to acknowledge that a lot of sophomoric dirty jokes will be made about the terminology in this article. He has thought of them all, so there is no need to leave them in the comments section.)

Except for the one I just thought of that is significantly better than all of the ones you mentioned above :-)

I think the most popular current explanation for supermassive formation is by merger. The story is, you start with an early Universe with smallish galaxies and reasonably sized black holes at the center (maybe the mass of a large globular cluster that didn't have enough angular momentum to survive collapse, being at the center of the cloud that formed the galaxy). Then these galaxies start eons of mergers with the black holes feeding along the way, and after billions of years of collisions and central black hole mergers, you see the monsters of today. Simulations show it's plausible (growth is exponential, as each cycle of merging doubles the mass of the central black holes, so mass increases a millionfold after 20 mergers), and we've observed black hole mergers directly. This gets the size correlation correct, as the more mergers of a galaxy, the more mergers of its black hole, but allows for outliers like this where for some reason a black hole lost its galaxy after undergoing many mergers, perhaps by being ejected from its galaxy by an ancient collision and carrying only a small region of surrounding stars with it.

This is still a very open question. I think merger is the popular option only by process of elimination. There seem to be no scenarios where enough mass could be close enough together to spontaneously collapse into supermassive black holes. However, we still do not understand the conditions/physics of the early universe well. There might be a mechanism for direct formation of supermassive black holes that no one has thought of.

But the rest of your explanation is almost certainly wrong. Current cosmology theory is that quasars were the accretion disks of supermassive black holes at the centers of early galaxies. So any theory of "supermassiveness" needs to allow for these things to have formed within a billion years of the Big Bang. It may still involve mergers of black holes, but to get enough mergers that early in the universe you'd have to be thinking about mergers of the holes at the centers of protogalaxies, rather than mergers of what we think of as true galaxies. It may have taken additional mergers to get to the extra-super-massive black holes (for lack of a better term) that we see in the biggest galaxies today, but the size range we think of as supermassive was almost certainly reached among the earliest galaxies.

As far as the galaxy in question, it really is a hard question. The stability of lenticular galaxies (and spirals) is believed to be the result of not having been perturbed since their early formation. Such galaxies still grow over time, by accreting much smaller galaxies, but true mergers or interactions with galaxies big enough to strip off big sections of a galaxy would almost certainly leave traces in the galactic structure.

But perhaps the stripping of material happened very early on, before the dust cloud around the SMBH settled into a star-forming disk.

As an aside, galaxies originally form disks for the same reason solar systems do. Clouds of dust and gas collapse due to gravity. Most gas and dust end up in the middle. But some of it ends up in orbit around the middle. Collisions/friction among those orbiting particles result in an averaging of angular momentum, such that gravity collapses the cloud into a single ecliptic. In solar systems, this cloud accretes into planets. In galaxies it accretes into stars. However, once these dust clouds have accreted into distinct objects, these objects will not settle back into a single ecliptic after being perturbed. There is not enough friction or collisions in the system. That is why mergers of spiral galaxies result in elliptical galaxies. In theory, elliptical galaxies cold settle back into spirals, but statistically, we'd be well past the heat death of the universe before that would be expected to happen.

As a futher aside, it is believed elliptical galaxies can be formed directly. Fast enough star formation stops the collision/friction cycle that would cause collapse into a flat spiral/lenticular shape.

TL;DR:

1) Based on our current understanding of galactic formation/evolution, SMBHs in the smaller part of the range appeared within a billion years after the Big Bang, so the category as a whole cannot be explained by the mergers of what we generally refer to as galaxies (but perhaps can be explained by the merger of early protogalaxies).

2) Whatever happened to give this galaxy it's high ratio of black hole to bulge must have happened really early in its lifetime. Potentially at or before the time that star formation began in its disk.